Electronic circuit



Sept. 11, 1951 J. DAHLINE 2,567,876

ELECTRONIC CIRCUIT Filed Dec. 9, 1948 3 Sheets-Sheet I LOAD Snvcntor P 11, 1951 L. J. DAHLINE 2,567,876

ELECTRONIC CIRCUIT Filed Dec. 9, 1948 3 Sheets-Sheet 5 s 1 230 use LOAD :LINE

2/5. 5 545 330 323 LINE 3 326 k 346 fig LOAD r325 F :LINE

INVENTOR.

LAWRENCE J. DAHLINE Patented ss eu, 1 951 annc'raomo cmoUrr Lawrence J. Dahline, Minneapolis, Minn., as-

lignor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn a corporation of Delaware Application December 9, 1948, Serial No. 64,348

14 Claims. (Cl. 175-320) 1 This invention relates to electronic circuits and in particular to those electronic circuits wherein momentary energization of electron discharge means continuously energizes a controlled circuit. It is therefore an object of the invention to devise an improved circuit of this type. Another object of the invention is to devise such a circuit of this type wherein deenergization of the controlled circuit is effected by a second momentary energization oi said discharge means.

. Another object of the invention is to devise such a circuit wherein either energization or deenergization of the controlled circuit operates to deenergize the discharge means.

Another object of the invention is to devise such a circuit wherein gas filled tubes may be used to advantage.

An advantage of this type of circuit wherein gas filled tubes are used is that upon energization of a gas filled tube a sufilcient electron flow is immediately passed to completely energize or deenergize the controlled circuit.

Another advantage of this type of circuit is that the tubes used have a long life expectancy because they are energized only momentarily.

These and other objects and advantages will be apparent from the following description and drawings in which:

Figure 1 shows one form of the invention utilizing a single tube and tour relays for both energizing and deenergizing the controlled circuit;

Figure 2 shows a modification of the invention utilizing separate tubes for energization and deenergization of the controlled circuit and using a single relay having a first winding and a bucking winding;

Figure 3 shows a modification of the invention utilizing separate tubes and separate relays ior energization and deenergization of the controlled circuit;

Figure 4 shows a modification of the invention utilizing a single tube and two relays in which the connections of the tube to the power source are reversed; and

Figure 5 shows a modification of the invention utilizing a single tube and two relays in which the connections of the voltage divider, used as a signal source, to the power source are reversed.

In the circuit of Figure 1 the single tube is energized by a signal from a voltage divider. Firing or the tube energizes a first relay which closes the energizing circuit to a second relay. The second relay, upon being energized, establishes its own holding, or energizing, circuit and further closes the energizing circuit to a third relay. Energization or the third relay reverses the connections 01' the voltage divider to the-line, or power source, resulting in deenergization of the tube and consequent deenergization of the first relay. Due to the establishment of the holding circuit for the second relay, however, the

second and third relays remain energized. When the controlling point of the voltagedivider again reaches the value to cause the tube to fire, the first relay is again energized and, due to new circuits closed through energization of the third relay, causes a fourth relay to be energized. Energization of the fourth relay opens the holding circuit of the second relay, deenergizing the having an anode l l, a starting anode l2 and a cathode II is supplied with an anode to cathode potential from a transformer It having a primary winding I5 and a secondary winding IS. The primary winding I5 of transformer I4 is supplied with line voltage from leads 20 and 2! as follows: from lead 2| through leads 22 and 24, transformer primary winding I5, leads 25 and 23 to lead 20. The voltage across secondary I6 is of the order of 325 volts.

A first relay 40 has a winding 4| with a condenser in parallel therewith for keeping winding ll energized upon alternate half cycles when tube II is not conducting, a fixed contact 44, and a movable contact 43 on an arm 45 for making electrical connection with fixed contact 44 upon energization of winding ll. The movable contact is biased out of engagement with contact 44 to separate therefrom during deenergization oi winding 4 I.

A second relay to has a winding 6|, a movable 3 and 19, movable contact 11 on arm 18 to make electrical connection with either fixed contact 16 or fixed contact 19, fixed contacts 80 and 83, and a movable contact 8| on arm 82 to make electrical connection with either fixed contact 88 or fixed contact 83. The movable contacts 13, 11 and 8| are biased out of engagement with contacts 15, 19 and 83 respectively to separate therefrom and to make electrical connection with contact 12, 16 and 88 respectivel during deenergization of winding 1 I.

A fourth relay 90 has a winding 9|, a fixed contact 92 and a movable contact 93 on an arm 94 to break connection with fixed contact 92 upon energization of winding 9i. The movable contact 93 is biased to make engagement with contact 92 during deenergization of winding 9|.

A voltage divider 58 has a limiting resistor ii, a balancing resistor 52 having a movable contact 53 for shorting out a portion thereof, a signal device, considered in the present description as a relative humidity element 54, a current limiting resistor 55, and an unbalancin resistor 56 the magnitude of which can vary dependin on the regulation desired. The unbalancing resistor 56 have a switch 51 in parallel therewith. Relative humidity element may be, though not necessarily must be, of the type disclosed in the patent to Dunmore, Number 2,285,421. The resistance of the element may vary from 50,000 ohms to 2 megohms, depending upon the humidity. Resistor 52 is adjusted so that tube 69 fires when the humidity reaches one of the desired limiting values. With the relays all deenergized, as shown, the voltage divider 50 is energized from transformer M as follows: from transformer secondary winding l6, through lead 26, resistor 5|, 52, 54, and 56, lead 59, movable arm 82- and movable contact 8| on arm 82 forming part of relay 10, fixed contact 80, lead 3i, and back to transformer secondary winding i6.

A load 26 may be placed across line voltage leads 28 and 2| by the followin circuit from line voltage lead 2| through leads 22 and 29, relay contacts 92 and 93, lead 98, relay contacts 62 and.64, lead 86, load 28, and lead 23 to line voltage lead 20. The load may be of such type as to control the condition to which the relative humidity element is responsive.

The plate to cathode potential of tube In is supplied from transformer secondary l6 through lead 26, resistance 21, lead 30, relay winding 4| of relay 40, plate cathode i3, leads '32 and 3| and back to the transformer secondary winding 6. A voltage regulator 34 is placed in parallel with relay winding 4| and tube i0 and is connected to lead 30 through lead 33 and to lead 3| through lead 35.

Values of components used in a successfully operated model are:

Operation of species of Figure 1 The operation of this circuit is as follows. When a satisfactory humidity condition is present the circuit is as shown in the drawing,

' that is, with all the relays in their deenergized position, and thus no voltage is applied to the load 28. Upon the relative humidity decreasing below a permissible value tube I0 will fire. jlhis is due to the increased resistance of relative humidity element 54 which raises the potential of the starting anode |2 with respect to cathode l8. When the tube i0 is energized, relay winding 4| will be energized, closing the contacts 43 and 44.

When contacts 43 and 44 are closed, relay winding 6| is energized by the following circuit: from power source lead 2| through lead 22, arm 45. movable contact 43, fixed contact 44, lead 46, arm 14, movable contact 13, fixed contact 12. lead 84, fixed contact 61, lead 96, relay winding 6|, leads 68 and 23 to power source lead 28.

When relay winding 6| is energized, relay contacts 62 and 64 and and 61 are closed. Closing of contacts 62 and 64 energizes the load 28 from the source through the previously described circuit. Closing of contacts 65 and 61 establishes a holding circuit for energizing relay winding Si by the following path: from power source lead 2| through leads 22 and 29, fixed contact 92, movable contact 93, arm 94, leads 98 and 99,-. arm 66, movable contact 65, fixed contact 61,

lead 96, relay winding 6|, and leads 68 and 28 to power source lead 29.

Closing of contacts 62 and 64 also energizes relay winding 1| by the following circuit: from power source lead 2| through leads 22 and 28. fixed contact 92, movable contact 98, arm 84,

lead 98, arm 63, movable contact 62, fixed con-u tact 64, lead 86, lead 81, relay winding 1|, and leads 88 and 23 to power source lead 28. Energization of relay winding 1| breaks electrical connection between contacts 12 and 13, 18 and 11, and and 8| and closes contacts 18 and 18, 11 and 19, and BI and 93. Breaking the connection between contacts 11 and 16 and contacts 8| and 80 and making connection between contacts 11 and 19 and contacts 8| and 88 reverses voltage divider 50 with respect to tube l8. With the relay windings previously deenergized the upper end of voltage divider 50 had been connected to anode of tube 0 through lead 88. contacts 11 and 16, leads 38 and 38 and relay winding 4| while the lower end of the voltage divider had been connected to cathode l3 through lead 59, contacts 8| and 88, and leads 3| and 32. With contacts 16 and 11 and 80 and 8| broken and contacts 11 and 19 and 8| and 88 closed the upper end of the voltage divider is connected to the cathode through lead 58, contacts 11 and 19 and leads 3| and 32 while the lower end of the voltage divider is connected to the anode through lead 59, contacts 8| and 88, lead 30 and relay winding 4|. This reversal oi. the voltage divider places the potential of the starting anode |2 negative with respect to the potential of cathode l3 at the instant of reversal and deenergizes tube I0. It is important to note that tube I0 has been energized only instantaneously and has been deenergized due to the reversal of the voltage divider connections upon energization of relay winding 1|. Thus the connectfon between contacts 43 and 44 is broken and relay winding 9| remains deenergized.

Deenergization of tube i0 deenergizes relay winding 4| breaking the connection between contacts 43 and 44. As has been noted, however. relay winding 6|, upon being energized established a holding circuit to,.continue the energization of relay winding 6| through a path by-passv ing relay contacts 43 and 44.

assure lead 24.

This energization of relay winding breaks the connection between the fixed contact 32 and movable contact 93. Breaking of this connection breaks the holding circuit energizing relay winding 6|, deenergizing relay winding H and opening the circuit to the load 23. Breaking the connection between contacts 62 and 64 also breaks the circuit energizing relay winding 1I,. permitting the movable contacts 13, 11 and 3| to return to their original deenergized position. This again reverses th voltage divider, dropping the potential on starter anode I2 below that potential on the cathode I3 and deenergizing tube I0. Breaking of the connection between contacts 13 and 15 breaks the energizing circuit of relay 50. Deenergization of tube I0 again deenergizes relay winding 4| and effects breaking of the connection between contacts 43 and 44 and the circuit is again in its original completely deenergized position.

M odification of Figure 2 In Figure 2 two gas filled tubes, H0 and I are used. Both tubes receive their signals from a single voltage divider I30. Upon one of the controlling points of the voltage divider reaching a predetermined value a first tube will fire, energizing one winding of the relay. Energization of this relay winding closes the energizing circuit to the load, establishes its own holding circuit and, in addition, breaks the energizing circuit to the first tube and closes the energizing circuit to the second tube. Energization of the load results in its operation to change the humidity condition and change the controlling point of the voltage divider which is effective upon the second tube to a predetermined value which causes the tube to fire. Firing of the second tube results in energization of the bucking winding in the relay to cancel the effect of the first winding and deenergize the relay to place the entire circuit in its original deenergized position.

A voltage divider I having a current limiting resistor I3I, a calibrating resistor I32 having a movable contact I33 for shorting out a portion thereof, a differential adjustment resistor I34, 9. relative humidity element I35 and a current limiting resistor I36 is connected across the line through leads I03 and I03.

Tube IIO has an anode III, a starting anode H2 and a cathode II3. Tube I20 ha an anode I2I, a starting anode I22 and a cathode I23.

A relay I has a relay winding HI and a second relay winding I42 which is called a bucking winding because when energized winding I42 counteracts the efi'ect of winding I and relay I40 is in effect deenergized. Condensers I43 and I44 are in parallel with relay windings HI and I 42 to hold windings HI and I 42 energized during the, alternate half cycles when tube I20 is not conducting. A movable contact I46 on arm I41 makes connection to fixed contact I through spring bias when the relay I40 is deenersized and to fixed contact I43 when the relay I44 is energized. A movable contact I50 on arm I5I makes contact with fixed contact I52 when th relay I 40 i energized and is biased out of engagement with contact I52 to separate therefrom upon deenergization of winding "I or energization of bucking winding I42.

When the relay I40 is deenergized a potential is placed across the plate and cathode in tube III through the following circuit: fromflpower lead I08 through lead II4, relay winding I, lead II5, movable arm I41, movable contact I46, fixed contact I45, lead II6, plate III, cathode H3 and lead II1, to power lead I09.v Connection to starting anode H2 is by lead II3 to a point on the voltage divider between the-calibrating adjustment resistor I32 and the differential adjustment resistor I34.

Connection to starting anode I22 of tube I20 is made through lead I24 to a movable contact I31 on the diiferential adjustment resistor I34.

When the relay I40 has its relay winding I4I energized a plate to cathode potential is placed across tube I20 by the following circuit: from power lead I08 through lead I25, arm I5I, movable contact I50, fixed contact I52, lead -v I26, cathode I 23, plate I2I, lead I21, relay winding I42, and lead I23 topower lead I03.

Operation of modification of Figure 2 The operation of the circuit shown in Figure 2 is as follows.

When the relative humidity decreases, the resistance of the relative humidity element I35 is increased and raises the potential of the starting anode II2 with respect to cathode H3 in tube IIO. When the potential of the starting anode II 2 is sufiiciently positive with respect to the potential on cathode H3, tube H0 will be enersized.

Energization of tube H0 energizes winding I and breaks the connection between contacts I45 and I46 and makes connection between contacts I46 and I 43. Energization of relay winding I also makes connection between relay contacts I50 and I52.

Upon making connection between contacts I46 and I 43 a holding circuit is established to retain the energization of relay winding I. This circuit extends from power lead I08 through lead I I4, relay winding I, lead II5, arm I41, movable contact I46, fixed contact I43, lead I53, and resistor I54, to power lead I09. Resistor I54 limits the amount of current which may'fiow through relay winding I when the relay is energized so as to be easily bucked by the current through winding I42 when tube I20 fires.

As a result of movable contact I46 breaking connection with fixed contact I45, the circuit energizing tube H0 is broken and tube- H0 is thus deenergized.

When the relay winding I is energized movable contact I50 makes connection with fixed contact I52 to energize the load 28 from the line by the following circuit: from line voltage lead I03 through lead I25, contacts I50 and I 52, lead I26, load 23, and lead I23 to power lead I09, and in addition places a potential across the plate and cathode in tube I20 by means of the fol-.

lowing circuit: from power lead I06 through lead I25, contacts I50 and I52, lead I26, cathode I23. anode .I2I, lead I21, relay "bucking winding I42 and lead I23 to power lead I 03. Thus, tube I20 is in a position to fire when the relative humidity element I35 has been decreased in resistance suf- I42 is energized and the effect is to neutralize the energization of winding I4I, permitting the movable contacts I46 and I50 to move from their energized position to their deenergized position. This breaks the circuit to tube I20 to deenergize this tube and also deenergize the bucking" winding I42; Also, when movable contact I46 breaks connection with fixed contact I48 relay winding I is deenergized and tube I is again in a position to fire upon application of a proper signal to starting anode II2. As the potential on the starting anode H2 in tube M0 is now too low to permit energization of tube M0 the entire circuit is again in its original completely deenergized position.

Modification of Figure 3 Figure 3 is quite similar to Figure 2 in that it has two gas filled tubes and a voltage divider all of which may be noted by the same reference numerals as has been done. The major diflerence, however, is that whereas in Figure 2 the circuit uses but one relay having two windings. one of which is a "bucking winding, in Figure 3 two relays are used.

Relay I60 has a winding I6I and a condenser I62 in parallel therewith to retain energization of winding I6I during the time it takes for movable contact I65 to move from contact I63 to contact I64. Two fixed contacts, I63 and I64, have a movable contact I65 on an arm I66 moving therebetween. Movable contact I65 makes connection with contact I64 when winding I6I is energized and is biased to make connection with contact I63 when the winding is deenergized. A contact "I on arm I12 makes connection with fixed contact I when the relay winding I6I is energized and is biased out of engagement with contact I10 to separate therefrom upon deenergization of winding I6 I A second relay I80 has a relay winding I8I and a condenser I82 in parallel therewith to hold winding I8I energized during alternate halt cycles when tube I20 is not conducting. A movable contact I84 on an arm I85 is biased to make contact with a fixed contact I83 when the relay I80 is in the deenergized position and is separated therefrom when the relay is energized.

When the circuit shown in Figure 3 is in the deenergized position as shown in the drawing a potential is placed across the tube I I0 in the following manner: from power lead I08 through tact I H also makes connection with fixed contact I10. Condenser I62 retains energization of relay winding I6I during the time it takes for movable contact I65 to move from fixed contact I63 to contact I64.

Relay winding I6I is then energized through the following holding circuit: from power lead I08 through lead I13, winding I6I, lead I14, arm I66, movable contact I85, fixed contact I64, lead I16, fixed contact I83, movable contact I84, arm I85 and lead I86, to power lead I08. A potential is also placed across the tube I by the following circuit: from power lead I08 through lead I11, arm I12, movable contact "I, fixed contact I10, lead I18,lead I26, cathode I28, plate I2I, lead I81, relay winding I8 I, and lead I88 to power lead lead I13, relay winding I6I, lead I14, arm I66,

movable contact I65, fixed contact I63, lead I15, plate III, cathode H3 and lead M1 to power lead I08.

Operatimz of the modification of Figure 3 The operation of the circuit shown in Figure 3 is as follows:

When the relative humidity is decreased to such value that the resistance of the relative humidity element I35 is increased to drive the potential on the starting anode I I2 of tube I I0 sufllcientlypositive with respect to the potential or cathode II3, tube 0 will fire. I

When tube H0 is energized relay winding I6I is nergized and movable contact I65 breaks connection with fixed connection I63 and .makes connection with fixed contact I60. Movable con- Breaking of the connection between contacts I63 and I64 opens the energizing circuit of tube H0 and the tube ceases firing. Relay winding I6I, however, remains energized through the holding circuit above recited. Load 28 is now energized by the following circuit: from power lead I08 through lead I11, contacts Ill and I10, leads I18 and I26, load '28 and lead I29 to power lead I09.

When the relative humidity has increased to such an extent due to operation of load 28 that starting anode I22 is sufiiciently positive with respect to cathode I28 in tube I20, tube I20 will be energized and energize relay winding I8I of relay I80.

Energization of relay winding I8I breaks the connection between fixed contact I83and movable contact I84. This breaks the holding circuit for energizing relay winding I6I in relay I60. Upon deenergization of relay winding I6I movable contacts I65 and "I move to their deenergized position. When movable contact I1 I breaks connection with fixed contact I10 the circuit to tube I20 is broken and deenergizes tube I20 and thus relay winding I8I and the entire circuit is then again in its original completely deenergized position.

Modification of Figure 4 In the circuit of Figure 4 a voltage divider provides the signal for a single gas filled tube which, when first energized, energizes a first of two relays. Energization of this relay closes an energizing circuit to a, load, establishes a holding circuit for the relay winding, and reverses the connections of the tube with respect to the line and, thus, to the voltage divider. The reversal of connections deenergizes the tube until the controlling point of the voltage divider reaches a new predetermined value to cause the tube to fire again and energize the second relay which breaks the holding circuit for the first relay so that the first relay is deenergized, reversing the tube connections back to their original position and resulting in the circuit in again resuming its original completely deenergized position.

In this modification a voltage divider having a difierential adjusting resistor 200, a calibration resistor 20I and a control element -202, considered in the following description as a humidity control element, is connected through limiting resistors 203 and 204 to a source of line voltage, not shown, as follows: from line voltage lead 205 through conductors 206 and 201, limiting resistor 208, diiferential adjusting resistor 200, calibration resistor 20I, humidity control element 202, limiting resistor 204, and conductors '2I0, 2H and 2I2 to line voltage lead 2I3.

aaeaaze Diilerential adjusting resistor 233 has a wiper arm 214 connected to one terminal 01 the resistor to by-pass a portion of the resistance it desired. Balancing resistor 231 has a wiper arm 215 connected to one terminal of the resistor to by-pass a portion of this resistance if so desired.

The junction between resistor 231 and control element 232 is the controlling point and is connected to a starting anode 215 o! a gas filled gridglow type of tube 211 through a conductor 220. In addition to starting anode 213 the grid-glow tube 211 has an anode 221 and a cathode 222.

A first relay 223 and a second relay 224 are also in the circuit Relay 223 has an energizing coil 225 across which is connected a resistor 225 and a condenser 221 for purposes to be described later. Relay 223 has a movable contact 230 operating between fixed contacts 231 and 232, a movable contact 233 operating between fixed contacts 234 and 235, a movable contact 235 operating between fixed contacts 231 and 243, and a movable contact 241 operating between fixed contacts 242 and 243.

The relay 224 has an energizing coil 244 across which are connected a resistor 245 and a condenser 245 in series for purposes to be described later. Relay 224 also has a movable contact 241 operating between fixed contacts 253 and 251. A load 252 is energized upon proper operation of the circuit. This load may be of the same type as load 23 shown in the circuit of the first three figures wherein energization of the load causes it to operate to increase the humidity aflecting the humidity control element 202.

Operation of the modification of Figure 4 With the elements in the position shown, the tube 211 is connected across the line from lead 235 through conductor 213, fixed contact 250, movable contact 241, conductor 252, movable contact 241, fixed contact 242, conductor 253, anode 231, 234, 231 and 242, respectively, to their energized position against fixed contacts 232, 235, 244, and 243. Firing of tube 211 charges up condenser 221. When tube 211 is deenergized the condenser discharges through relay winding 225 to hold the winding energized until the movable contacts have moved to their energized positions.

When relay winding 225 is energized the movable contacts move to their energized positions as above described and the load 252 is then energized from line voltage lead 235 through conductors 235 and 253, movable contact 233, fixed contact 232. conductor 254, load 252, and conductor 211 to line voltage lead 213.

At the same time relay winding 225 remains energized by utilizing its own holding circuit wherein movable contact 241 makes connection with fixed contact 243. Relay winding 225 is then energized as follows: from line voltage lead 235 throagh conductor 213, fixed contact 253, movable contact 241, conductor 252, movable contact 241, fixed contact 243, conductors 254, and

235, relay winding 225, and conductors 251, 211 and 212 to line voltage lead 213.

Movable contact 233 moves from fixed contact 234, opening the shorting circuit around diii'erential adjusting resistor 233, and against fixed contact 235 which is electrically isolated from the remainder of the circuit.

Anode 221 of tube 211, which was originally connected to line voltage lead 205 through lead 213, contacts 253 and 241, lead 252, contacts 241 and 242 and lead 253 is now connected to line voltage lead 213 through leads 212 and 253, relay winding 244, lead 251, contacts 235 and 243 and leads 251 and 253 while the cathode 222 which was originally connected to line voltage lead 213 through leads 212, 211 and 251, relay winding 225 and leads 255 and 255 is now eitectively connected to line voltage lead 235 through lead 213, contacts 253 and 241, lead 252, contacts 241 and 243 and leads 254 and 255.

Upon this reversal of the tube connections tube 211 is deenergized and will remain deenergized as long as the control element retains the same value of impedance which it has to cause original firing of the tube. As a result relay winding 244 remains deenergized.

Upon the humidity control element 202 attaining a second predetermined value due to operation of the energized load in changing the humidity affecting the element 232 the potential 01' the starting anode 215 oi tube 211 is such as to cause tube 211 to fire thus energizing relay winding 244 of relay 224 and charging up condenser 245. Energization of relay winding 244 causes movable contact 241 to break connection with fixed contact 253 and move against fixed contact 251. During the time it takes for the movable contact to move from its deenergized to its energized position condenser 245 discharges through relay winding 244 to keep the winding momentarily energized. As was noted previously the connection between fixed contact 253 and movable contact 241 forms a part of the holding circuit ior relay winding 225. With the energization of relay winding 244 this connection is broken and relay winding 225 is deenergized, permitting movable contacts 233, 233,235, and 241 to move from their energized position against fixed contacts 232, 235, 243 and 243, respectively, to their deenergized positions against fixed contacts 231, 234, 231 and 242.

With the breaking of the connection between movable contact 233 and fixed contact 232 the energizing connection to the load 252 is broken while the making of the connection between movable contact 233 and fixed contact 234 again places an effective short circuit across the difierential adjusting resistor 233. The movement of movable contacts 235 and 2 41 to their deenergized position again reverses the connections of anode 221 and cathode 222 to the line voltage leads so that the energization of tube 211 is now the same as it was originally. Breaking of the connection between movable contact 235 and fixed contact 243 also breaks the energizing circuit of relay winding 244 to deenergize relay 224. The breaking of the connection between movable contact 241 and fixed contact 243 also breaks the holding circuit for energizing relay winding 225 and thus relay 223 is deenergized.

Because of the potential placed on starting anode 215 due to the instant condition of humidity and its effect upon humidity control element 202 tube 211 is also deenergized and the 1 l entire circuit is in its original completely deenerglzed position.

Modification of Figure 5 sidered for description purposes as a humidity control element. Wiper arm 233 moves along calibration resistor 230 and is connected to one terminal of calibration resistor 280 while diiferential adjusting resistor 23! has a wiper arm 234 connected to one terminal of the resistor and traversing the length thereof. Differential adjusting resistor 28! and humidity control element 282 are connected together through a conductor 285.

The junction between resistor 23! and control element 202, as represented by conductor 285, is connected to a starting anode 286 of a gas filled grid-glow type of tube 281 through a conductor 290. Gas tube 281 also has, in addition to starting anode 286, an anode 29! and a cathode 292.

A first relay 293 and a second relay 294 are also included in the circuit.

Relay 293 has a relay winding 295 in parallel with a resistor 296 and a condenser i291 and operates five movable contacts 300, 30L 302, 303 and 304, which in their deenergized position make connection with fixed contacts 305, 301, 309, 3M

and 3!3 respectively, and in their energized position make connection with fixed contacts 303, 308, 3!0, 3!2 and 3.

Relay 294 has a relay winding M5 in parallel with a resistor 3!6 and a condenser 3H for purposes to be described later. Relay 296 also has a movable contact 320 which in its deenergized position makes connection with fixed contact 3211 while in its energized position it makes connection with fixed contact 322. Ihe circuit is energized from line voltage leads 323 and 323. A load 325 having terminals 323 and 327i is energized upon proper operation of this circuit. Load 325 may be such as to decrease the humidity aifecting element 282 upon energization of the load.

The voltage divider comprising resistors 230 and 28! and control element 282 is energized from the line as follows: from power lead 323 through leads 330 and 331, direct voltage blocking condenser 332, lead 333, movable contact 302, fixed contact 309, leads 334 and 335, resistors 239 and 28!, lead 285, control element 232, leads 336 and 331, fixed contact 3! movable contact 303, lead 340, direct voltage blocking condenser 3M, and leads 342, 343 and 344 to line voltage lead 326.

In the particular modification shown, the load 325 is shown to be energized when the circuit is in its generally deenergized position as shown. The energizing circuit for the load 325 is as follows: from line voltage lead 323 through leads 330 and 345, movable contact 300, fixed contact 305, and lead 346 to terminal 326 of load 325, terminal 321 of load 325, and lead 341 to line voltage lead 324.

Tube 281 is operatively connected across the line as follows: from line voltage lead 323, through lead 350, relay winding 295 in parallel with resistor 296 and condenser 291, lead 358, movable 12 contact 304, fixed contact 3!3, lead 352, anode 29!, cathode 292, and leads 353, 343 and344 to line voltage lead 324.

Operation in the modification of Figure 5 As is shown in the drawing the terminal of resistor 23!! connected to lead 335 is connected to line voltage lead 323 and the terminal of control element 232 connected to lead 336 is connected to line voltage lead 324 while plate 29! of tube 231 is connected to line voltage lead 323 and the cathode 292 is connected to line voltage lead 324 through circuits previously traced.

When the impedance value of control element 232 reaches such a value due to the humidity condition as to cause the potential on starting anode 206 to reach a given predetermined value, tube 231 fires, causing energizationof relay winding 295, positioned in the anode circuit of the tube.

Energization of relay winding 295 causes the movable contacts 300, 30!, 302, 303 and 304 to move to their energized position against fixed contacts 306, 308, 3!0. 3!2, and 3. Movement of movable contact 300 from fixed contact 305 to fixed contact 306 breaks the cnergization circuit to the load 325 and thus the load is no longer energized.

Movement of movable contact 30! away from fixed contact 301 against fixed contact 308 completes a short circuit across the differential adjusting resistor 28! through lead 354 connected to one terminal of resistor 23!, contacts 30! and 303 and lead 355 connected to the other terminal of resistor 28 I, and thus changes the potential across the various components remaining in the voltage divider.

Movement of movable contact 302 away from fixed contact 309 breaks the circuit between the calibration resistor 230 to line voltage lead 323, previously traced, while movement of movable contact 303 against fixed contact 3!2 makes the connection between calibration resistor 280 and line voltage lead 324 through leads 335 and 356, contacts 3!2 and 303, lead 340, blocking condenser 34! and leads 342, 343 and 344. The movement of movable contact 303 away from fixed contact 3H breaks the connection between control element 232 and line voltage lead 324, previously traced, while movement of movable contact 302 against fixed contact 3!0 makes a connection between control element 232 and line voltage lead 323 through leads 336 and 351, contacts 3!0 and 302, lead 333, blocking condenser 332 and leads 33! and 330. It is thus seen that the connections between the voltage divider and the line voltage leads are reversed upon energization of relay winding 295.

Movement of movable contact 304 away from fixed contact 3!3 breaks the energizing circuit to relay winding 295 momentarily but because of the charge which has been built up upon condenser 291 during the firing of tube 281, the relay winding 295 remains momentarily energized. This is because condenser 291 discharges through resistor 296 and relay winding 295 when the charging circuit to condenser 291 has been broken. When movable contact 304 breaks connection with fixed contact 3!3 it makes connection with fixed contact 3 and thus relay winding 295 is energized from the line voltage leads by the following circuit: from line voltage lead 323 through lead 350, relay winding 295 in parallel with condenser 291 and resistor 296, lead 35!, movable contact 304, fixed contact 3I4,

leads I and 252, anode leads an, 3", and 3 Tube 201 is dehoweventhatrelaywinding lllisnowinaposi- Upon firing of tube m relay winding us is energized and a. charge is built up on condenser I" in parallel with the relay winding SIS.

1 tion of relay winding 3|5 causes movable contact Hi to break connection with fixed contact 32] and make connection with fixed contact 322.

The breaking of the connection between movable contact 322 and fixed contact 32! breaks the holding circuit for relay winding 295 and causes deenergization of relay 2", resulting in movable contacts ill, Ill, 3'2, 303 and 3 moving to their deenergized position.

As movable contact I breaks connection with fixed contact I", the energizing circuit for relay winding 3|! is broken but the charge which is then built up upon condenser 315 discharges through resistor 3| and relay winding iii to hold it momentarily in energization after the connection between movable connection 300 and fixed contact I" is broken when movable contact I" breaks connection with fixed contact 3" the energizing circuit to tube 281 is also broken while the movement of movable contacts "2 and 302 to their deenergized positiom again reverse the connections of the voltage divider with respect to the line voltage leads so that .the connection between the voltage divider and the line is now just as it was originally. The breaking of the energizing circuit for tube 2|! causes tube 2" to cease firing while the new potential placed on starting anode 2" due to the reversal oi the voltage divider with respect to the electrodes of the tube prevents tube 2" from again firing immediately. Relay winding 295 is now again in the anode circuit of tube 2|! and bezause this tube is not firing the relay winding 225 remains deenergized while, as has been pointed out above, relay winding ll! is also deenergized due to the breaking oi its energizing circuit. Due to the connection made between contacts Ill and "I the load 225 is again energizedacross the line.

I4 It is thus seen that the circuit has passed through a complete cycle of operation which in brief is as iollows: firing of tube 281 causes energiza'tion oi relay 2" which reverses the connections of the voltage divider to the line voltage leads and causes deenergization of tube 281. .A second firing of tube 221 causes energization of relay 2 which results in deenergization of relay 2 causing the connection between the voltage divider and the line voltage leads to resume their original position and deenergize tube 201 and relays 2N and 2".

While I have shown and described five specific embodiments or modifications of my invention it will be understood that these are for purposes of illustration only and that my invention is to be claimed only by the scope of the appended claims.

I claim as my invention:

1. In combination: a condition responsive device connected across a source of alternating voltage; electron discharge means connected across the source oi! alternating voltage; a controlled circuit; means operatively connecting said discharge means to said controlled circuit to control the energization thereof; input circuit means operatively connecting said condition responsive device to said discharge means so that upon the condition aiiecting the condition responsive device assuming a first predetermined value the discharge means is so energized as to connect said controlled circuit across the source of alternating voltage for energization oi said controlled circuit; means efiective, upon energization of said discharge means, to cause deenergization of said discharge means while retaining said controlled circuit in the energized condition independently of the deenergization of said discharge means; and means effective, upon said controlled circuit being energized and the condition controlling said condition responsive device assuming a second predetermined value, to cause said discharge means to be so energized as to deenergize both said controlled circuit and said discharge means.

2. In combination: a voltage divider containing a variable impedance; electron discharge.

means; a controlled device; means operatively connecting said controlled device to said discharge means to control the energization of said controlled device; means operatively connecting said voltage divider to said discharge means so that upon the voltage across said variable impedence assuming a first predetermined value the discharge means is so energized as to energize said controlled device; means effective, upon energization of said discharge means, to cause deenergization of said discharge means while retaining said controlled device energized independently of the deenergization of said discharge means; and means effective, upon the voltage across said variable impedance assuming a second predetermined value, to so energize said discharge means as to deenergize both said controlled device and said discharge means.

3. In combination: a condition responsive device having a continually varying impedance value dependent upon a condition to be controlled; electron discharge means; a controlled device for controlling the condition afiecting the condition responsive device; means operatively connecting said discharge means to said controlled device to control the energization thereof; means operatively connecting said condition responsive device to said discharge means so that asemsve upon the condition responsive device being caused to assume a first predetermined value the discharge means is so energized as to energize said controlled device and effect a changing of the condition aifecting the condition responsive device; means eifective, upon energization of said discharge means, to cause deenergization oi! said discharge means while retaining said controlled device. energized independently or the deenergization of said discharge means; and means efi'ective, upon said controlled device being energized and said condition responsive device being caused to assume a second predetermined value, to cause said discharge means to be so energized as to deenergize both said controlled device and said discharge means.

4. In combination: a condition responsive device having a continually varying impedance value dependent upon a condition to be controlled connected across a source of alternating voltage; electron discharge means connected acrossthe source of alternating voltage; a controlled device for controlling the condition affecting the condition responsive device; means operatively connecting said discharge means to said controlled circuit to control the energization thereof; means operatively connecting said condition responsive device to said discharge means so that upon the condition responsive being caused to assume a first predetermined value the discharge means is so energized as to connect said controlled device across the source of alternating voltage so as to energize said controlled device and efi'ect a changing of the condition effecting the condition responsive device; means efiective, upon energization of said discharge means; to cause deenergization of said discharge means while retaining said controlled device energized independently of the deenergization of said discharge means; and means efiective upon said controlled device being energized and said condition responsive device being caused to assume a second predetermined value, to cause said discharge means to be so energized as to deenergize both said controlled device and said discharge means.

5. In combination: a voltage divider containing a variable impedance; a pair of gas filled electron discharge devices; a controlled circuit; means-selectively energizing one of said discharge devices from said voltage divider upon the voltage acrosssaid variable impedance assuming a predetermined value; means selectively energizing the other of said discharge devices from said voltage divider upon the voltage across said impedance assuming a second predetermined value; means operatively connecting said devices to said circuit in such a manner that said circuit is energized upon energization of one of said devices'and is deenergized upon energization of the other of said devices; and means operatively connected to said devices to cause deenergization of said devices upon energization thereof.

6. In combination: a source of signal voltage; a first and a second electron discharge device; a controlled circuit; input circuit means electrically connecting said source to said discharge devices in such a manner that, upon said signal voltage assuming a first predetermined value. said first discharge device is energized; means so operatively connecting said first discharge device and said controlled circuit that, upon energization of said first device, said controlled circuit is energized, deenergizing said first device and establishing a holding circuit effective lndei6 pendently of the deenergization of said first device for continuing energization of said controlled circuit; and means, including said input circuit means, effective, upon said controlled circuit being energized and said signal voltage assuming a second predetermined value, to energize said second discharge device and effect deenergization of said controlled circuit and said discharge device.

7. In combination: a voltage divider containing a variable impedance; a first and a second electron discharge device; a first relay winding; a second relay winding; a controlled device; means so connecting said first discharge device to said voltage divider that upon the voltage across said variable impedance assuming a first predetermined value said first discharge device is energized; means so operatively connecting said first relay winding to said first discharge device and to said controlled device that said first relay winding is energized upon energization of said first discharge device to energize said controlled device, deenergize said first discharge device, and retain energization of said first relay winding independently of said first discharge device; means so connecting said second discharge device to said voltage divider that upon the voltage across said variable impedance assuming a second predetermined value and said first relay winding being energized said second discharge device is energized; and means so operatively connecting said second relay winding to said second discharge device and to said first relay winding that said second relay winding is energized upon energization of said second discharge device to deenergize said first relay winding, and thus said controlled device, said second relay winding. and said second discharge device.

3. The combination as claimed in claim 7 wherein the first relay winding is the primary winding of a relay and the second relay winding is a bucking winding of the same relay so that energization of the second relay winding neutralizes the magnetomotive force produced by the primary winding.

9. In combination: a source of signal voltage; a first and a second electron discharge device; a relay having a first winding and a bucking winding; means so operatively connecting said source and said first device that, upon said signal voltage assuming a first predetermined value. said first device is energized; means so electrically connecting said first device and said first relay winding that energization of said first device causes energization of said first winding; means effective. upon energization of said first winding, to deenergize said first device and establish a holding circuit effective independently of the deenergization of said first device; means so operatively connecting said source and said second device that, upon said signal voltage assuming a second predetermined value, said second device is energized; means so electrically connecting said second device and said bucking winding that energization of said second device causes energization of said bucking winding; and means effective, upon energization of said bucking winding, to deenergize said second device, said first winding and said bucking winding.

10. An electronic circuit having in combination: a source of power; a voltage divider containing a variable impedance; a first and a second gas filled electron discharge device; a relay having a first and a second winding; a load; means energizing said voltage divider from said power source; means electrically connecting said first discharge device across said power source; means electrically connecting said second discharge device across said power source; means electrically connecting said first winding of saidrelay in series with said first discharge device across said power source; means electrically connecting said second winding of said relay in series ing a second predetermined value and causing energization of said second device and said second winding, opening the contacts of said relay to deenergize said first winding and saidsecond device.

11. In combination: a voltage divider utilized as a source of signal voltage; a first and a second electron discharge device; a relay having a first and a second winding; means so electrically connecting said voltage divider and said first discharge device that, upon said signal voltage assuming a first predetermined value, said first device is energized; means so electrically connecting said first discharge device and said first winding of said relay that, upon energization of said first device, said first winding is energized; means so operatively connected to said first winding that, upon energization thereof, a holding circuit is effected to retain energization of said first winding; further means so operatively connected to said first relay winding that, upon energization thereof, said first discharge device is deenergized; means so electrically connecting said voltage divider and said second discharge device that, upon said signal voltage assuming a second predetermined value, said second device is energized; means so electrically connecting said second discharge device and said second relay winding that, upon energization of said second device, said second winding is energized; means so operatively connected to said second winding that, upon energization thereof, said holding circuit for said first winding is deenergized; and further means so operatively connected to said second winding that, upon energization thereof, said second device is deenergized, deenergizing said second winding.

12. The combination as claimed in claim 7 wherein the first and the second relay windings are windings of two separate relays and energization of the second relay winding breaks the energizing circuit for said first relay winding.

charge device to said source; means connecting said discharge device to said voltage divider such that said device is energized upon said variable impedance attaining a first predetermined value; means energizing said first relay upon energization of said discharge device; means, eflective upon energization of said first relay, to reverse the connections of said device to said source and cause deenergization of said device; means reenergizing said device upon said variable impedance attaining a second predetermined value; means energizing said second relay upon reenergization of said device; and means, eifective upon energization of said second relay, to deenergize ously energizing said first relay;

ing said device upon said variable impedance at- 13. In combination: a voltage divider having a portion thereof comprising a variable impedance; a gas filled electron discharge device; a first relay; a second relay; a source of voltage; means energizing said voltage divider from said source; means operatively connecting said dissaid first relay and cause the connections of said device to said source to revert to their original positions and further result in deenergization of said second relay.

14. In combination: a voltage divider having a portion thereof comprising a variable impedance; a gas filled electron discharge device; a first relay; a second relay; a source of voltage; means energizingly connecting said voltage divider from said source; means operatively connecting said discharge device to said source; means connecting said discharge device tosaid voltage divider such that said device is energized upon said variable impedance attaining a first predetermined value; means energizing said first relay upon energization of said discharge device; means, effective upon energization of said first relay, to reverse the energizing connections of said voltage divider to said source and cause deenergization of said device; contact means operated upon by said first relay for closing an energizing circuit, upon energization of said first relay for continumeans reenergiztaining-a second predetermined value; means energizing said second relay upon reenergization of said device; and means effective upon energization of saidsecond rela to deenergize said 'first relay and cause the connections of said voltage divider to said source to revert to their original positions and further result in deenergization of second relay.

LAWRENCE J. DAHLINE.-

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

